Taiwan Semiconductor Manufacturing Co. filed court papers Monday in U.S. district court detailing alleged corporate espionage on the part of its mainland China competitor, Semiconductor Manufacturing International Corp..

TSMC first filed its suit against SMIC in U.S. District Court of Northern California in San Francisco last December, alleging infringement of five U.S. patents as well as stolen trade secrets. Among other claims, TSMC alleged that SMIC recruited TSMC employees and asked them to bring TSMC process technology with them to SMIC.

In its filing Monday, TSMC included signed affidavits of former SMIC engineers who stated that they personally witnessed SMIC's knowing use of TSMC technology. TSMC asked that the identity of one such engineer remain sealed because of the witness' fear of reprisal from Chinese government officials.

According to the documents filed Monday, TSMC specifically cites 0.18-micron chips manufactured by SMIC for Irvine, Calif.-based Broadcom Corp. The Taiwanese foundry examined chips extracted from a Linksys wireless notebook adapter.

"From TSMC' s examination, it is apparent that SMIC's 0.18-micron process and chips sold to Broadcom both were created using TSMC' s patented and trade-secret processing techniques, and also contain TSMC patented and trade secret features resulting from SMIC's use of TSMC process steps," Mickey Ken, deputy director of the CTO's office at TSMC alleged in his affidavit filed with federal court.

TSMC further alleges that the chips bear little resemblance to foundry Chartered Semiconductor's 0.18-micron process.

A hearing in the case in which a judge may decide on SMIC's motion for dismissal is scheduled for April 23.